/* Soot - a J*va Optimization Framework
 * Copyright (C) 2000 Patrick Lam
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the Sable Research Group and others 1997-1999.  
 * See the 'credits' file distributed with Soot for the complete list of
 * contributors.  (Soot is distributed at http://www.sable.mcgill.ca/soot)
 */


package soot.jimple.toolkits.scalar;
import soot.*;
import java.util.*;
import soot.util.*;

/** Provides an user-interface for the AvailableExpressionsAnalysis class.
 * Returns, for each statement, the list of expressions available before and after it. */
public interface AvailableExpressions
{
    /** Returns a List containing the UnitValueBox pairs corresponding to expressions available before u. */
    public List getAvailablePairsBefore(Unit u);

    /** Returns a List containing the UnitValueBox pairs corresponding to expressions available after u. */
    public List getAvailablePairsAfter(Unit u);

    /** Returns a Chain containing the EquivalentValue objects corresponding to expressions available before u. */
    public Chain getAvailableEquivsBefore(Unit u);

    /** Returns a Chain containing the EquivalentValue objects corresponding to expressions available after u. */
    public Chain getAvailableEquivsAfter(Unit u);
}
